Field
This disclosure relates generally to adjustable focal length lenses, and more specifically, to use of a glucose monitoring system as a control input to adjustable focal length lenses.
Related Art
Persons who have diabetes can have high blood sugar levels over a prolonged period of time due to either that person's pancreas not producing enough insulin or that person's body not responding properly to the insulin produced. Type 1 diabetes results from a body failing to produce enough insulin, while Type 2 diabetes can begin with insulin resistance. High blood sugar levels can produce a variety of short term symptoms in a diabetic, including, for example, frequent urination, increased thirst, increased hunger, and the like.
Another symptom of fluctuating blood sugar levels in diabetics is fluctuating vision, which can make a single pair of corrective lenses ineffective. Blood sugar levels affect the ability of the eye lens to maintain sharp focus by causing the lens to swell, and thereby changing the curvature of the lens. In some cases, when blood sugar is high, near vision can be good and distance vision can deteriorate. On the other hand, when blood sugar is low, near vision can deteriorate and distance vision can improve.
Variable focus lenses can be used to adjust a prescription for fluctuating eyesight. Such lenses provide a mechanical mechanism for changing the prescription (e.g., injection of a fluid into a chamber containing an elastic membrane between two lenses to alter curvature of the membrane, or changing a relationship between two lenses) or an electronic mechanism for changing the prescription (e.g., liquid crystals and the like). But traditional mechanisms require manual adjustment of the lens focus, which can be bothersome and interrupts normal activities.
The use of the same reference symbols in different drawings indicates identical items unless otherwise noted. The figures are not necessarily drawn to scale.